This invention relates generally to an apparatus for measuring the interface between two fluids, and in particular to an apparatus for measuring the pressure differential between two elevations in an earth borehole to provide an indication of the fluid interface.
The desirability of locating fluid interfaces in an earth borehole has been long recognized in the art of well logging. However, the prior art systems have generally been plagued by the drift effects of temperature and pressure or, in attempting to overcome such problems, have been very complex and expensive.
It is therefore the primary object of the present invention to provide an improved apparatus for measuring the interface between fluids in an earth borehole.
It is a further object of the invention to provide an improved apparatus for measuring the fluid interface within the earth borehole which is substantially unaffected by the effects of temperature and pressure.
The objects of the invention are accomplished, generally, by providing an earth borehole instrument having a pair of bellows equally spaced from a differential pressure transducer and by the provision of means to expose the exterior of the differential pressure transducer to the pressure of the borehole fluid of interest.